Properties of Through-Hardening Bearing Steels Produced by BOF Blowing Metallurgy and by Electric Arc Furnace with Ladle Metallurgy

This paper discusses the cleanliness of through-hardening bearing steels produced by different melting and deoxidation processes. Macroscopic cleanliness is tested by the step-down and blue fracture test, and microscopic cleanliness is classified according to three rating methods. Cleanliness values of the air-melted heats are compared with remelted steels. Oxide inclusions are related to the oxygen contents of the heats, titanium-carbonitrides to the titanium contents, and sulfide inclusions to the sulfur contents of the heats. Machinability is effected more by carbide grain sizes than by sulfur contents. Ingot- and continuous cast steels are compared on cleanliness and segregation.